The 100-metre-tall cranes are to be used at Singapore's APM Terminal, specifically to service new 'triple E' class container ships of Maersk Line.
Algeciras, the busiest container port in the Iberian Peninsula, handled 4.3 million TEU last year. The installation of these cranes is expected to position the port as one of the leading container terminals in Europe.
The cranes manufactured in Shanghai underwent a 50-day voyage to Algeciras, with the unloading at port taking eight days.
ISS operations manager for Algeciras and Iberia said Julian Isola, "We first arranged the entry clearance with the harbour master and liaised with all parties, including the pilots and the tugs.
"The vessel had to continually adjust her drafts during the crane discharge, in order to ensure proper stability of the vessel, so we also shared these plans accordingly."